thedoc wrote:Yes, time scale might be one of the factors, but science doesn't know if energy is entering or exiting the Universe. Several years ago I speculated that the cause of the expansion of the universe was not due to space stretching, as some scientists have stated, but because there is more space coming into existence. I don't like the idea that space is elastic and can stretch or contract, but space is more like a perfect fluid, in that it can conform to whatever the shape of the container but is incompressible. In the large scale structure of the universe there are large voids, or under dense areas surrounded by sheets of galaxies. In these under dense areas there could be places where new space, matter and energy are coming into existence pushing older space and galaxies out in front of it. This old space and the galaxies contained in it could collect in the cusps between the voids, and this would account for the observed structure of the universe.
I think time scales are worth considering. Photons theoretically coming from 14 billion light years away would not have been noticed yet.
I like the superfluid analogy of space but I would argue that space is thoroughly compressible, as is everything aside from perhaps whatever resides in the centre of supermassive black holes. That near-singularity (I suspect that actual singularities are only theoretic constructs, like infinity), would be even more dense than neutron stars, the most dense objects ever observed, and they probably cannot be further crushed.
Re: voids, it's been hypothesised that the voids between the strands of the cosmic web could be largely comprised of antimatter.
http://phys.org/news/2011-04-antimatter ... nsion.html. Antimatter to itself behaves in what we think of as a gravitationally normal way but, to the perspective of matter, antimatter would seem gravitationally repulsive.
It may even be that there are antimatter galaxies existing in our voids. The possibility also makes the idea of intergalactic travel even more daunting and impossible that it already seems; nothing that is matter could survive contact with antimatter.
For all we know, our idea of ever-increasing entropy may only be a phase of the universe. After all, the rate of inflation has changed before. Further, a significant x-factor regarding the future universe may be the activities of future hyper-intelligent life that are a billion or more years ahead of us. If we can terraform the Earth, hyper advanced civilisations will surely affect much more, especially if they can communicate and coordinate with others.
Most consider the latter idea far-fetched but, when the rate of change is considered, any life that is a billion years more advanced than us would be as different to us as we are from bacteria. It would seem that only the speculative and questionable "hard barrier" hypothesis could suggest that such beings will never exist in the cosmos.
